Nobody said anything about primary weapon, though. But NOLF1 and Deus Ex 1 both managed to incorporate decent sniping options. It's a fun aspect of the game, especially if you're playing as a stealth character.
The counter-example I was thinking of was Mass Effect. You had a separate skill for sniping, and there were situations where it was quite useful, but in the vast majority of combats, it was far weaker than all three other weapons options. Any character specializing in SRs to the exclusion of other weapons was probably going to be rather gimped, which I think is a balance flaw to be avoided.
I never found it all that useful because the sniper swayed like crazy and you couldn't get a decent shot. Also, no headshot damage bonus means this just failed.